Blaise Pascal

Blaise Pascal (Clermont-Ferrand, 1623 - Paris, 1662) was a French mathematician, physicist and philosopher, as well as a Catholic theologian and apologist. He lived in the middle of the scientific revolution of the seventeenth century, alongside Descartes, and his work ranges from geometry and the calculus of probability to hydrostatics and the reflection on faith. Today he is remembered mainly for his experiments on pressure and vacuum, for his mechanical calculator and for the Pensées, a collection of fragments published after his death in which he examines the human condition.

He was born into a family of magistrates. His father, Étienne Pascal, oversaw his education, and the boy showed an early gift for mathematics. At sixteen he wrote a treatise on conic sections that impressed Descartes, and he is credited with a theorem that still bears his name. In 1631 the family moved to Paris, and in 1639 his father was appointed tax commissioner in Rouen. There, at nineteen, Blaise devised a machine able to add and subtract, the Pascaline. It was technically remarkable, but too expensive to succeed commercially.

In 1647 Pascal published work on the vacuum and atmospheric pressure, building on Torricelli's experiments and taking part in the debate with those who defended the old idea that nature abhors a vacuum. Around 1654 he corresponded with Fermat about gambling problems, and out of that exchange came the mathematical theory of probability. In those years he also wrote the Traité du triangle arithmétique, a systematic account of binomial coefficients.

His life took a religious turn in 1646, when he and his sisters came into contact with Jansenism, a Catholic movement inspired by Augustine. After an intense religious experience in November 1654, he largely set aside scientific research to devote himself to theology and philosophy. He wrote the Lettres provinciales (1656-1657), a defence of the Jansenists against the Jesuits, written in an ironic prose that is often regarded as a model of classical French. His Pensées gather the material for an apology of Christianity that he never finished.

In them Pascal portrays the human being as a contradiction: frail as a reed, yet able to think. Reason, though valuable, is not enough to answer the deepest questions about God, the soul and the meaning of life; for these, one needs the heart, an intuitive and affective disposition enlightened by grace. His famous wager argues that, since we cannot know with certainty whether God exists, believing is the more prudent choice, because the potential gain is infinite and the loss finite. The argument has been debated for centuries, but it has earned him recognition as a forerunner of themes later developed by Kierkegaard and Nietzsche.

Pascal died in Paris at thirty-nine, after a long illness. His influence reaches mathematics, through the triangle and probability theory; physics, through the unit of pressure that bears his name; and the philosophy of religion and of existence.